It is very common in the inverter industry. How to check the fault after the inverter has been used for a long time?
In order to make the inverter run normally, it must be installed in strict accordance with the technical specifications and instructions of the inverter when it is used, and it must meet the requirements of the input power supply and use environment. The commonly used input voltage of the inverter is three-phase 380V480 V, which can fluctuate continuously by 10%. The frequency of the shortwave input power supply is 50/60Hz, and the fluctuation is 5%. Dedicated frequency converters are another matter.
1. The detection of the rectifier circuit in the static detection of the frequency converter
When the inverter is statically tested, it is necessary to test the rectifier circuit after the inverter is powered off. First, remove all the output wires of the inverter; secondly, find the positive and negative DC circuits in the inverter, and then turn the knob of the multimeter to the diode block. Third, connect the black probe and the red probe to the positive and negative poles of the DC bus and the three-wire output line respectively, and record the three voltage values displayed by the multimeter; if the six measured values of the multimeter are equal, it indicates that the rectifier bridge is normal, otherwise it indicates There is a problem with the rectifier bridge and needs to be adjusted or replaced.
Inverter circuit detection in the static detection of frequency converter
In the static test of the inverter, the inverter circuit test and the rectifier circuit test are almost the same, and both are performed when the inverter is turned off. The difference is that in the inverter circuit test, the multimeter knob should be turned to resistance×10 gears, the red and black probes should be connected to the negative pole of the DC bus respectively, and contact a set of 3-wire outputs to record the inverter circuit separately And record the resistance value. The three resistance values displayed last time are equal, and the value displayed last time is OL. Use the same method to connect the black probe to the positive pole of the DC bus, and the measurement results are consistent, indicating that the inverter is normal. Otherwise, it indicates that there is a problem with the inverter module IGBT of the inverter, and the IGBT module needs to be replaced.
2. about the dynamic detection of the inverter
The dynamic test can only be performed after all the static tests are normal. On the one hand, before powering on the inverter, it is necessary to check whether the input voltage and rated voltage level of the inverter are the same; on the other hand, it is necessary to check whether each terminal and the module are loose and whether the connection is normal. After the inverter is powered on, first detect the fault, and determine the cause and type of the fault according to the fault code; secondly, check whether the set parameters and the rated load parameters are the same. If the inverter is not connected to the load and is in no-load operation, please measure whether the three-wire output voltage is consistent.
Post time: May-10-2021